1. Field
Some example embodiments relate to light-sensing apparatuses and/or methods of driving the same, and more particularly, to light-sensing apparatuses in which a light-sensor transistor and a switch transistor in a light-sensing pixel may have the same oxide semiconductor transistor structure, and/or methods of driving the light-sensing apparatuses to improve the operating reliability of the light-sensing apparatuses.
2. Description of the Related Art
An oxide semiconductor transistor may be a transistor using an oxide semiconductor as a material of a channel. For example, an oxide semiconductor transistor may include a substrate, a gate disposed on the substrate, a gate insulating film disposed on the substrate and the gate to cover a periphery of the gate, an oxide semiconductor channel layer disposed on the gate insulating film, and a source and a drain disposed on both sides of the channel layer. Such an oxide semiconductor transistor may have a high sensitivity to light and may be used as a light-sensing element. The sensitivity to light may depend on the oxide semiconductor used in the channel layer. If an oxide semiconductor is used as a channel layer in an oxide semiconductor transistor, a threshold voltage and a drain current of the oxide semiconductor transistor may vary according to the wavelength and/or amount of incident light.
An oxide semiconductor transistor may be used instead of a photodiode as a light-sensing element. In addition, oxide semiconductor transistors may generate a larger photoelectric current than photodiodes. Accordingly, if the oxide semiconductor transistor is used as a light-sensing element, a capacitor that is generally used in a light-sensing pixel in order to accumulate charges generated due to a photoelectric current for a desired (and/or alternatively predetermined) period of time may be omitted. For example, the light-sensing pixel may include only the oxide semiconductor transistor for sensing light and a switch transistor for outputting data. Accordingly, the oxide semiconductor transistor may be used in various devices for sensing light. For example, the oxide semiconductor transistor may be used in an imaging device and/or an optical touch screen panel.